Crate fuzed_iterator

Fuzed iterator

fuzed-iterator is a Rust library crate that provides a simple iterator wrapper that causes a panic if the iterator is used after it has once returned None.

Many iterators in std implement the FusedIterator trait, which guarantees that the iterator will never return Some after returning None. This may make programmers incorrectly assume that any iterator works like a FusedIterator, leading to bugs when a non-fused iterator is used.

The Fuze wrapper provided by this crate can be used to wrap any iterator, causing a panic if the iterator is used after returning None for the first time. This can be used to catch bugs where a non-fused iterator is used in a context where a fused iterator is expected. In your unit tests (or integration tests), pass iterators through Fuze to your functions that expect an iterator (not necessarily fused), and the tests will panic if the function calls Iterator::next excessively.

Example

use fuzed_iterator::IteratorExt;
let mut iter = (0..3).fuze();
assert_eq!(iter.next(), Some(0));
assert_eq!(iter.next(), Some(1));
assert_eq!(iter.next(), Some(2));
assert_eq!(iter.next(), None);
iter.next(); // Another `next` call would panic!

License

MIT or Apache 2.0, at your option

Structs

• Fuze
  Iterator wrapper that panics if next is called after it returns None

Traits

• IteratorExt
  An extension trait that adds the fuze method to iterators